This invention relates in general to a system for training sonar operators by means of a simulated PPI display on the screen of a CRT. In particular, the invention relates to a simulated PPI display system using digital to video techniques.
Effective operator training requires a display as realistic as possible. Realism requires that a large number of effects, such as wakes, reverberations, and target echo, be simulated. Realism also requires a system having fast signal processing time. With many of the well known analog systems of the prior art, the necessity of a manual input for each effect severely limited the number of effects which could be simulated at any one time. Also, the slow signal processing time of analog devices detracts from the realism of their displays. In another type of known simulator, simulated input information is introduced directly into the sonar transducers of an actual sonar system. This has a disadvantage in that it can be used only on a ship or other installation where real sonar systems exist. A further disadvantage is that if the sonar system is inoperative, or undergoing maintenance, the simulation system cannot be used for training. Prior art systems using digital to video techniques require large quantities of hard-wired, special purpose signal generators resulting in high initial cost, high maintenance expense and large storage space.